Signed-off-by: NDavid Sterba <dsterba@suse.com>

The return value of flush_space was used to have significance in the
early days when the code was first introduced and before the ticketed
enospc rework. Since the latter got introduced the return value lost any
significance whatsoever to its callers. So let's remove it. While at it
also remove the unused ticket variable in
btrfs_async_reclaim_metadata_space. It was used in the initial version
of the ticketed ENOSPC work, however Wang Xiaoguang detected a problem
with this and fixed it in ce129655 ("btrfs: introduce tickets_id to
determine whether asynchronous metadata reclaim work makes progress").
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Userspace transactions were introduced in commit 6bf13c0c ("Btrfs:
transaction ioctls") to provide semantics that Ceph's object store
required. However, things have changed significantly since then, to the
point where btrfs is no longer suitable as a backend for ceph and in
fact it's actively advised against such usages. Considering this, there
doesn't seem to be a widespread, legit use case of userspace
transaction. They also clutter the file->private pointer.

So to end the agony let's nuke the userspace transaction ioctls. As a
first step let's give time for people to voice their objection by just
WARN()ining when the userspace transaction is used.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ move the warning past perm checks, keep the has-been-printed state;
  we're ok with just one warning over all filesystems ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Superblock is read and written using buffer heads, we need to set the
bdev blocksize. The magic constant has been hardcoded in several places,
so replace it with a named constant.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There are two independent parts, one that writes the superblocks and
another that waits for completion. No functional changes, but cleanups,
reformatting and comment updates.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Polish the helper:
* drop underscores, no special meaning here
* pass fs_devices, as this is what the API implements
* drop noinline, no apparent reason for such simple helper
* constify uuid
* add comment
Signed-off-by: NDavid Sterba <dsterba@suse.com>

There are two helpers called in chain from one location, we can merge the
functionaliy.

Originally, alloc_fs_devices could fill the device uuid randomly if we
we didn't give the uuid buffer. This happens for seed devices but the
fsid is generated in btrfs_prepare_sprout, so we can remove it.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The function submit_extent_page has 15(!) parameters right now, op and
op_flags are effectively one value stored to bio::bi_opf, no need to
pass them separately. So it's 14 parameters now.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Unify types of local variables and parameters that store various
REQ_* values to unsigned int.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NDavid Sterba <dsterba@suse.com>

Signed-off-by: NDavid Sterba <dsterba@suse.com>

This function prints an informative message and then continues
dev-replace. The message contains a progress percentage which is read
from the status. The status is allocated dynamically, about 2600 bytes,
just to read the single value. That's an overkill. We'll use the new
helper and drop the allocation.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We'll want to read the percentage value from dev_replace elsewhere, move
the logic to a separate helper.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All sorts of readahead errors are not considered fatal. We can continue
defragmentation without it, with some potential slow down, which will
last only for the current inode.
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We can safely use GFP_KERNEL, the function is called from two contexts:

- ioctl handler, called directly, no locks taken
- cleaner thread, running all queued defrag work, outside of any locks
Signed-off-by: NDavid Sterba <dsterba@suse.com>

We don't need to restrict the allocation flags in btrfs_mount or
_remount. No big filesystem locks are held (possibly s_umount but that
does no count here).
Signed-off-by: NDavid Sterba <dsterba@suse.com>

One of the error handling paths in __add_reloc_root contains btrfs_panic()
followed by some other code. As the name implies what it does is print
some error message and call BUG, naturally what follow afterwards is not
invoked. So remove this extra code.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This also adjusts the respective callers in other files. Those were
found with -Wunused-parameter.

btrfs_full_stripe_len's mapping_tree - introduced by 53b381b3
("Btrfs: RAID5 and RAID6") but it was never really used even in that
commit

btrfs_is_parity_mirror's mirror_num - same as above

chunk_drange_filter's chunk_offset - introduced by 94e60d5a ("Btrfs:
devid subset filter") and never used.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

clear_super - usage was removed in commit cea67ab9 ("btrfs: clean
the old superblocks before freeing the device") but that change forgot
to remove the actual variable.

max_key - commit 6174d3cb ("Btrfs: remove unused max_key arg from
btrfs_search_forward") removed the max_key parameter but it forgot to
remove references from callers.

stripe_len - this one was added by e06cd3dd ("Btrfs: add validadtion
checks for chunk loading") but even then it wasn't used.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

find_raid56_stripe_len statically returns SZ_64K which equals BTRFS_STRIPE_LEN.
It's sole caller is __btrfs_alloc_chunk and it assigns the return value to ai
variable which is already set to BTRFS_STRIPE_LEN. So remove the function
invocation altogether and remove the function itself. Also remove the variable
since it's only aliasing BTRFS_STRIPE_LEN and use the define directly. Use
the occassion to simplify the rounding down of stripe_size now that the value
we want it to align is a power of 2.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NQu Wenruo <quwenruo.btrfs@gmx.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

No functional changes, just make the code more self-explanatory.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

btrfs_new_inode() is the only consumer move it to inode.c,
from ioctl.c.
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

find_workspace() allocates up to num_online_cpus() + 1 workspaces.
free_workspace() will only keep num_online_cpus() workspaces. When
(de)compressing we will allocate num_online_cpus() + 1 workspaces, then
free one, and repeat. Instead, we can just keep num_online_cpus() + 1
workspaces around, and never have to allocate/free another workspace in the
common case.

I tested on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM. I mounted a
BtrFS partition with -o compress-force={lzo,zlib,zstd} and logged whenever
a workspace was allocated of freed. Then I copied vmlinux (527 MB) to the
partition. Before the patch, during the copy it would allocate and free 5-6
workspaces. After, it only allocated the initial 3. This held true for lzo,
zlib, and zstd. The time it took to execute cp vmlinux /mnt/btrfs && sync
dropped from 1.70s to 1.44s with lzo compression, and from 2.04s to 1.80s
for zstd compression.
Signed-off-by: NNick Terrell <terrelln@fb.com>
Reviewed-by: NOmar Sandoval <osandov@fb.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The helpers append "\n" so we can keep the actual strings shorter. The
extra newline will print an empty line.  Some messages have been
slightly modified to be more consistent with the rest (lowercase first
letter).
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The current code was erroneously checking for
root_level > BTRFS_MAX_LEVEL. If we had a root_level of 8 then the check
won't trigger and we could potentially hit a buffer overflow. The
correct check should be root_level >= BTRFS_MAX_LEVEL .
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NQu Wenruo <quwenruo.btrfs@gmx.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

For a missing device, btrfs will just refuse to mount with almost
meaningless kernel message like:

 BTRFS info (device vdb6): disk space caching is enabled
 BTRFS info (device vdb6): has skinny extents
 BTRFS error (device vdb6): failed to read the system array: -5
 BTRFS error (device vdb6): open_ctree failed

This patch will print a new message about the missing device:

 BTRFS info (device vdb6): disk space caching is enabled
 BTRFS info (device vdb6): has skinny extents
 BTRFS warning (device vdb6): devid 2 uuid 80470722-cad2-4b90-b7c3-fee294552f1b is missing
 BTRFS error (device vdb6): failed to read the system array: -5
 BTRFS error (device vdb6): open_ctree failed
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

As we use per-chunk degradable check, the global
num_tolerated_disk_barrier_failures is of no use.

We can now remove it.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

The last user of num_tolerated_disk_barrier_failures is
barrier_all_devices().
But it can be easily changed to the new per-chunk degradable check
framework.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Just the same for mount time check, use btrfs_check_rw_degradable() to
check if we are OK to be remounted rw.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Now use the btrfs_check_rw_degradable() to check if we can mount in the
degraded mode.

With this patch, we can mount in the following case:
 # mkfs.btrfs -f -m raid1 -d single /dev/sdb /dev/sdc
 # wipefs -a /dev/sdc
 # mount /dev/sdb /mnt/btrfs -o degraded
 As the single data chunk is only on sdb, so it's OK to mount as
 degraded, as missing one device is OK for RAID1.

But still fail in the following case as expected:
 # mkfs.btrfs -f -m raid1 -d single /dev/sdb /dev/sdc
 # wipefs -a /dev/sdb
 # mount /dev/sdc /mnt/btrfs -o degraded
 As the data chunk is only in sdb, so it's not OK to mount it as
 degraded.
Reported-by: NZhao Lei <zhaolei@cn.fujitsu.com>
Reported-by: NAnand Jain <anand.jain@oracle.com>
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Introduce a new function, btrfs_check_rw_degradable(), to check if all
chunks in btrfs is OK for degraded rw mount.

It provides the new basis for accurate btrfs mount/remount and even
runtime degraded mount check other than old one-size-fit-all method.

Btrfs currently uses num_tolerated_disk_barrier_failures to do global
check for tolerated missing device.

Although the one-size-fit-all solution is quite safe, it's too strict
if data and metadata has different duplication level.

For example, if one use Single data and RAID1 metadata for 2 disks, it
means any missing device will make the fs unable to be degraded
mounted.

But in fact, some times all single chunks may be in the existing
device and in that case, we should allow it to be rw degraded mounted.

Such case can be easily reproduced using the following script:
 # mkfs.btrfs -f -m raid1 -d sing /dev/sdb /dev/sdc
 # wipefs -f /dev/sdc
 # mount /dev/sdb -o degraded,rw

If using btrfs-debug-tree to check /dev/sdb, one should find that the
data chunk is only in sdb, so in fact it should allow degraded mount.

This patchset will introduce a new per-chunk degradable check for
btrfs, allow above case to succeed, and it's quite small anyway.
Signed-off-by: NQu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: NAnand Jain <anand.jain@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
[ copied text from cover letter with more details about the problem being
  solved ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

When btrfs fails the checksum check, it'll fill the whole page with
"1".

However, if %csum_expected is 0 (which means there is no checksum), then
for some unknown reason, we just pretend that the read is correct, so
userspace would be confused about the dilemma that read is successful but
getting a page with all content being "1".

This can happen due to a bug in btrfs-convert.

This fixes it by always returning errors if checksum doesn't match.
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

In btrfs_full_stripe_len/btrfs_is_parity_mirror we have similar code which
gets the chunk map for a particular range via get_chunk_map. However,
get_chunk_map can return an ERR_PTR value and while the 2 callers do catch
this with a WARN_ON they then proceed to indiscriminately dereference the
extent map. This of course leads to a crash. Fix the offenders by making the
dereference conditional on IS_ERR.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Many commits ago the data space_info in alloc_data_chunk_ondemand used to be
acquired from the inode. At that point commit
33b4d47f ("Btrfs: deal with NULL space info") got introduced to deal with
spurios cases where the space info could be null, following a rebalance.
Nowadays, however, the space info is referenced directly from the btrfs_fs_info
struct which is initialised at filesystem mount time. This makes the null
checks redundant, so remove them.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

All callers of flush_space pass the same number for orig/num_bytes
arguments. Let's remove one of the numbers and also modify the trace
point to show only a single number - bytes requested.

Seems that last point where the two parameters were treated differently
is before the ticketed enospc rework.
Signed-off-by: NNikolay Borisov <nborisov@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Several distributions mount the "proper root" as ro during initrd and
then remount it as rw before pivot_root(2). Thus, if a rescan had been
aborted by a previous shutdown, the rescan would never be resumed.

This issue would manifest itself as several btrfs ioctl(2)s causing the
entire machine to hang when btrfs_qgroup_wait_for_completion was hit
(due to the fs_info->qgroup_rescan_running flag being set but the rescan
itself not being resumed). Notably, Docker's btrfs storage driver makes
regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT
(causing this problem to be manifested on boot for some machines).

Cc: <stable@vger.kernel.org> # v3.11+
Cc: Jeff Mahoney <jeffm@suse.com>
Fixes: b382a324 ("Btrfs: fix qgroup rescan resume on mount")
Signed-off-by: NAleksa Sarai <asarai@suse.de>
Reviewed-by: NNikolay Borisov <nborisov@suse.com>
Tested-by: NNikolay Borisov <nborisov@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Repeating the same computation in multiple places is not
necessary.
Signed-off-by: NEdmund Nadolski <enadolski@suse.com>
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

When called with a struct share_check, find_parent_nodes()
will detect a shared extent and immediately return with
BACKREF_SHARED_FOUND.
Signed-off-by: NEdmund Nadolski <enadolski@suse.com>
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NLiu Bo <bo.li.liu@oracle.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

Since backref resolution is CPU-intensive, the cond_resched calls
should help alleviate soft lockup occurences.
Signed-off-by: NEdmund Nadolski <enadolski@suse.com>
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

This patch adds a tracepoint event for prelim_ref insertion and
merging.  For each, the ref being inserted or merged and the count
of tree nodes is issued.
Signed-off-by: NJeff Mahoney <jeffm@suse.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>